Switch supporting method

ABSTRACT

The present application discloses a switch supporting method comprising: an eNB sends a path switching request message to an MME to notify the MME of information on a bearer remaining unchanged; the MME reserves the bearer remaining unchanged and does not trigger a deactivation process for the bearer remaining unchanged; the MME sends a modify bearer request message to an SGW. With the present application, data loss can be avoided and service continuity is ensured when a UE moves in a small cell scenario.

TECHNICAL FIELD

The present invention relates to wireless communication technologiesand, more particularly, to a switch supporting method.

BACKGROUND ART

Modern mobile communication tends to provide users with multimediaservices at high transfer rates more and more. FIG. 1 is a systemarchitecture diagram of the System Architecture Evolution (SAE). In thisfigure,

a User Equipment (UE) 101 is a terminal device for receiving data. AnEvolved Universal Terrestrial Radio Access Network (E-UTRAN) is a radioaccess network including a macro base station (eNodeB/NodeB) to providea UE with a wireless network interface. A Mobility Management Entity(MME) 103 is responsible for managing a mobile context, a sessioncontext and security information of a UE. A Serving Gateway SGW (SGW)104 mainly provides user plane functions, and may be located in the samephysical entity as the MME 103. A Packet Data Network Gateway (PGW) 105is responsible for functions such as charging and lawful interceptionand may be located in the same physical entity as the SGW 104. A Policyand Charging Rules Function (PCRF) entity 106 provides a policy ofQuality of Service (QoS) and charging rules. A Serving GPRS Support Node(SGSN) 108 is a network node device to provide routing for datatransmission in a Universal Mobile Telecommunications System (UMTS). AHome Subscriber Server (HSS) 109 is a home ownership subsystem of the UEand is responsible for protecting user information such as a currentposition of the UE, an address of a service node, user securityinformation, and a packet data context of the UE.

3GPP proposes in Release 12 (Rel-12) demands on enhancement of a smallcell. As shown in FIG. 2, target scenarios of small cell enhancementincludes a scenario where there is macro cell coverage and a scenariowhere there is no macro cell coverage and enhancement for indoor andoutdoor, ideal and non-ideal backhaul.

In a case where there is macro cell coverage, a technology that carrieraggregation between different base stations can be applied is proposed.A macro cell and a small cell may operate at different frequency bands.There are multiple architectures for the technology of applying carrieraggregation between different base stations, e.g., a Radio AccessNetwork based separation architecture and a Core Network (CN) basedseparation architecture. The CN based separation architecture means thatfor a bearer established on a pico cell (pico), data are directly sentto the pico by an SGW of the core network and are not forwarded by auser plane via a macro cell (macro).

At present, there is not a solution to how to correctly notify the corenetwork of switch of bearers for this CN based separation architectureyet.

Especially, there are the following specific problems if an existingpath switching process is to be used to notify the core network ofswitch of bearers.

DISCLOSURE OF INVENTION Technical Problem

Problem I, after a UE hand over from a source base station to adestination base station and the destination base station receives ahandover complete message from the UE, the destination base stationsends a path switching message to notify the core network that downlinkinformation of a bearer needs to be switched. If the number of bearerscontained in an MME UE context is for example 3 and the number ofbearers contained in the path switching message is 2, the MME thinksthat an access network implicitly releases the bearer that is notcontained in the path switching message and thus the MME will trigger abearer deactivation process. And, an SGW will discard received data andwill not send a downlink data notification to the MME when receivingdata on the bearer. As for cases of CA between different base stations,if in a case a bearer at a pico is switched to another pico and a bearerat a macro remains unchanged, notifying the MME in the above manner willresult in that the bearer at the macro is released. Thus, data loss iscaused and service continuity and user experience are affected. If in acase only a bearer at a macro is switched from one base station toanother base station and a bearer at a pico remains unchanged, it willbe resulted in that the bearer at the pico is released innocently. Thus,data loss is caused and service continuity and user experience areaffected.

Problem II, the MME will assign a new MME UE S1AP ID to the UE whenreceiving the path switching message. If S1 is only present between theMME and an eNB in a inter-eNB CA architecture, in a case where the eNBremains unchanged, the MME does not need to assign an MME UE S1AP ID tothe UE. Otherwise, there will be two logic connections for the UE in asame interface, which is an error.

Problem III, the MME will provide a new pair of NH and NCC to a basestation when receiving the path switching message. In dependence on howa security mechanism is made when inter-eNB CA is implemented, the MME'sproviding a new pair of NH and NCC to a base station may result in thatthe NCCs at the UE and at the network side do not match.

In the inter-eNB CA architecture, there is a master eNB which terminatethe S1 between the eNB and the MME and/or terminate the RRC between theeNB and UE. Normally, master eNB is eNB. Therefore, in above, macro asmaster eNB is taken as example. This does not exclude that other basestation can be master eNB.

Solution to Problem

The present invention provides a switch supporting method which cannotify a core network of switch of bearers correctly and solves theabove specific problems. Thereby, correct processing of switch for a UEduring its movement in a small cell scenario is ensured and thus dataloss is avoided, service continuity is ensured and user experience isimproved.

A switch supporting method comprising:

sending, by a eNB, a path switching request message to an MME to notifythe MME of information on a bearer remaining unchanged;

reserving, by the MME, the bearer remaining unchanged;

and sending, by the MME, a modify bearer request message to an SGW.

Preferably, notifying the MME of information on a bearer remainingunchanged comprises: including a list of identifiers of bearersremaining unchanged in the path switching request message.

Preferably, notifying the MME of information on a bearer remainingunchanged comprises: including in the path switching request messageindication information for indicating the MME that a bearer not in alist of identifiers of bearers to be switched is not released.

Preferably, the MME keeps an SGW serving the UE unchanged afterreceiving the information on a bearer remaining unchanged.

Preferably, the MME notifies in the modify bearer request message theSGW of context information of the bearer remaining unchanged.

Preferably, the MME notifies the SGW of context information of thebearer remaining unchanged in one of the following manners:

including in the modify bearer request message a list of identifiers ofbearers remaining unchanged. The context information of those bearersremains unchanged; and

including in the modify bearer request message context information of abearer to be modified and context information of a bearer to be deleted,and taking, by the SGW, context information of a bearer that is notincluded in the context information of a bearer to be modified or in thecontext information of a bearer to be deleted as context information ofa bearer remaining unchanged.

Preferably, the SGW reserves a received downlink data packet for abearer whose bearer context information remains unchanged.

A switch supporting method comprising:

sending, by a eNB, a path switching request message to an MME to notifythe MME to reuse an MME UE S1AP ID prior to switch;

sending, by the MME, a path switch request confirmation message to theeNB and sending the MME UE S1AP ID prior to switch to the base station.

Preferably, to notify the MME to reuse an MME UE S1AP ID prior to switchcomprises one of the following manners:

including in the path switching request message indication informationfor reusing an MME UE S1AP ID prior to switch;

notifying in the path switching request message the MME of informationon a bearer remaining unchanged for indicating the MME to reuse an MMEUE S1AP ID prior to switch;

including in the path switching request message an Evolved Cell GlobalIdentifier (ECGI) to notify the MME to reuse an MME UE S1AP ID prior toswitch by using the same serving cell or the same serving base stationfor the UE prior to and after the switch.

A switch supporting method comprising:

sending, by a eNB, a path switching request message to an MME andnotifying in the path switching request message the MME to reuse asecurity context prior to switch;

sending, by the MME, a security context prior to switch to the eNB.

Preferably, notifying in the path switching request message the MME toreuse a security context prior to switch comprising:

including in the path switching request message indication informationfor reusing a security context prior to switch for indicating the MME toreuse a security context prior to switch;

notifying in the path switching request message the MME of informationon a bearer remaining unchanged for indicating the MME to reuse asecurity context prior to switch;

including in the path switching request message an Evolved Cell GlobalIdentifier (ECGI) to notify the MME to reuse a security context prior toswitch by using the same serving cell or the same serving base stationfor the UE prior to and after the switch.

As can be seen from the above technical solutions, in accordance with aswitch supporting method provided by the present invention, a eNBnotifies the MME of presence of a bearer remaining unchanged andinformation of the bearer when sending a path switching request messageto an MME. The MME reserves the bearer remaining unchanged and sends amodify bearer request message to an SGW to notify the SGW of contextinformation of the bearer remaining unchanged so that the SGW does notdiscard the data packet but notifies the MME that new data are receivedafter receiving a data packet of the bearer. With the above method,correct processing of switch for a UE during its movement in a smallcell scenario can be ensured and thus data loss is avoided and servicecontinuity is ensured.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a system architecture diagram of an existing SAE;

FIG. 2 shows a deployment scenario for enhancement of a small cell;

FIG. 3 is a schematic diagram illustrating a switch supporting method ofnotifying a core network of switch of bearers in accordance with thepresent invention;

FIG. 4 is a schematic diagram illustrating a switch supporting method ofnotifying an MME that an MME UE S1AP ID does not need to be assigned inaccordance with the present invention;

FIG. 5 is a schematic diagram illustrating a switch supporting method ofnotifying an MME that a new security context is not needed in accordancewith the present invention;

FIG. 6 is a schematic diagram illustrating a flow of embodiment I ofsupporting switch in accordance with the present invention; and

FIG. 7 is a schematic diagram illustrating a flow of embodiment II ofsupporting switch in accordance with the present invention.

MODE FOR THE INVENTION

The present invention is hereinafter described in detail with referenceto the drawings so as to make the objective, technical means and meritsthereof clearer.

FIG. 3 is a schematic diagram illustrating a switch supporting method ofnotifying a core network of switch of bearers in accordance with thepresent invention. The switch supporting method comprises the followingsteps.

In step 301, an eNB sends a path switching request message to a MME tonotify the MME of information on a bearer remaining unchanged (no switchand no release) and information on a switched bearer. The path switchingrequest message contains a list of bearers to be switched.

The eNB notifies the MME of information on a bearer remaining unchangedin one of the following several manners.

Manner I: including a list of identifiers of bearers remaining unchangedin the path switching request message. The MME knows, from the list ofidentifiers of bearers, bearers that are not switched or released(reserved in the original cell). The MME reserves the bearers remainingunchanged and does not trigger a bearer deactivation process for thebearers. For bearers present in the UE contexts that are not containedin a list of identifiers of bearers remaining unchanged or in a list ofidentifiers of bearers to be switched in the path switching requestmessage, the MME thinks that a base station impliedly releases thesebearers and thereby triggers a deactivation process for the bearers.

Manner II: including in the path switching request message indicationinformation for indicating to the MME that bearers not contained in alist of identifiers of bearers to be switched in the path switchingrequest message are not released. The MME knows from the indicationinformation that bearers present in the UE context but not contained inthe path switching request message are not implicitly released by thebase station, and thus reserves these bearers remaining unchanged anddoes not trigger a deactivation process for the bearers not contained inthe path switching request message.

The MME keeps an SGW serving the UE unchanged and does not select a newSGW for the UE when a path switching request message received by the MMEcontains information on a bearer remaining unchanged.

In step 302, the MME sends a modify bearer request message to the SGW.The MME does not contain a bearer remaining unchanged in a bearercontext to be deleted.

The MME notifies the SGW of context information of bearers to be keptunchanged in one of the following several manners.

Manner I: including context information of bearers to be modified andcontext information of bearers to be deleted in the modify bearerrequest message. The SGW thinks that bearers present in the UE contextof the SGW but not contained in the modify bearer request message (notbearers to be modified or not bearers to be deleted) are not changed andthus does not discard but reserves the downlink data packet and sends adownlink data notification to the MME when receiving a downlink datapacket in the bearer.

Manner II: including in the modify bearer request message a list ofidentifiers of unchanged bearers. Thereby, the SGW knows that thebearers are not changed and thus does not discard but reserves thedownlink data packet and sends a downlink data notification to the MMEwhen receiving a downlink data packet in the bearer.

With the above processing, presence of bearers remaining unchangedduring switch can be indicated to the MME. Thereby, it is ensured thatthose bearers are not deleted and assure no data loss.

FIG. 4 is a schematic diagram illustrating a switch supporting method ofnotifying an MME that an MME UE S1AP ID does not need to be assigned inaccordance with the present invention. The switch supporting methodcomprises the following steps.

In step 401, an eNB sends a path switching request message to a MME. TheeNB notifies the MME of information on a bearer remaining unchanged andinformation on a switched bearer. The MME is notified with a pathswitching request that an MME UE S1AP ID does not need to be assigned.

The eNB notifies the MME that a MME UE S1AP ID does not need to beassigned and the MME UE S1AP ID prior to switch is to be reused in oneof the following manners.

Manner I: including in the path switching request message explicitindication information that an MME UE S1AP ID does not need to beassigned.

Manner II: including information on bearers remaining unchanged in thepath switching request message. The information on bearers remainingunchanged may take one of the several forms given in step 301, e.g., alist of identifiers of bearers remaining unchanged or information forindicating that a bearer not in a list of identifiers of bearers to beswitched is not released. Thereby, the MME is notified that an MME UES1AP ID does not need to be assigned and the MME UE S1AP ID prior toswitch is to be reused.

Manner III: the MME knows that an MME UE S1AP ID does not need to beassigned and the MME UE S1AP ID prior to switch is to be reused,according to comparison of an Evolved Cell Global Identifier (ECGI)contained in the path switching request message to the ECGI of the cellwhere the UE is before the path switching request message is received,i.e., by using information that the serving cells or serving basestations prior to and after the switch of the UE are the same (an ECGIcontains an identifier of the PLMN and an identifier of a cell and theidentifier of a cell contains an identifier of a base station, and thusthe identifier of a base station can be acquired from the ECGI).

In step 402, the MME sends a path switching request confirmation messageto the eNB. Herein, the MME sends the original MME UE S1AP ID to theeNB. Thereby, the logical signaling connection of the UE between the eNBand the MME is kept unchanged and unique.

With the above processing manners shown in FIG. 4, in a case where apart of bearers are switched (the control plane node for the UE is keptat the source base station), the MME sends the MME UE S1AP ID of the UEprior to the switch to a base station and a new MME UE S1AP ID will notbe assigned for the UE. Thereby, it is avoided that two logicconnections for the UE appear in the same interface and successfulperforming of the switch is ensured.

FIG. 5 is a schematic diagram illustrating a switch supporting method ofnotifying a MME that a new security context is not needed in accordancewith the present invention. The switch supporting method comprises thefollowing steps.

In step 501, an eNB sends a path switching request message to a MME. TheeNB notifies the MME of information on a bearer remaining unchanged andinformation on a switched bearer. The MME is notified in the pathswitching request message that a new security context is not needed andthe security context prior to the switch is to be reused.

The eNB notifies the MME that a new security context is not needed andthe security context prior to the switch is to be reused in one of thefollowing several manners.

Manner I: including in the path switching request message explicitindication information that a new security context is not needed.

Manner II: including information on bearers remaining unchanged in thepath switching request message. The information on bearers remainingunchanged may take one of the several forms given in step 301, e.g., alist of identifiers of bearers remaining unchanged or information forindicating that a bearer not in a list of identifiers of bearers to beswitched is not released. Thereby, the MME is notified that a newsecurity context is not needed and the security context prior to switchis to be reused.

Manner III: the MME knows that a new security context is not needed andthe security context prior to switch is to be reused, according tocomparison of an Evolved Cell Global Identifier (ECGI) contained in thepath switching request message to the ECGI of the cell where the UE isbefore the path switching request message is received, i.e., by usinginformation that the serving cells or serving base stations prior to andafter the switch of the UE are the same (an ECGI contains an identifierof the PLMN and an identifier of a cell and the identifier of a cellcontains an identifier of a base station, and thus the identifier of abase station can be acquired from the ECGI).

In step 502, the MME sends a path switching request confirmation messageto the eNB. Herein, the MME sends the security context prior to switchto the eNB. Thereby, synchronization of the security contexts betweenthe eNB and the MME and between eNB and the UE is maintained.

With the above processing shown in FIG. 5, in a case where a part ofbearers are switched (the control plane node for the UE is kept at thesource base station), the MME sends the security context prior to theswitch to a base station and a new security context is not be assigned.Thereby, it will not result in that the NCCs at the UE and at thenetwork side do not match, and thus performing of the switchsuccessfully and a service continuity is ensured.

Detailed implementation of the above switch supporting methods in thepresent application is hereinafter described by means of specificembodiments.

Embodiment I of supporting switch in accordance with the presentinvention is shown in FIG. 6. This embodiment can be used in a scenariowhere a eNB serving a UE remains unchanged and is ready to switch a partof bearers of the UE from the eNB to a pico base station or from a picobase station 1 to a pico base station 2. The figure and the followingdescription are given with an example that the eNB switches a part ofbearers of the UE from the eNB to a pico base station, but are alsoapplicable to a scenario where the eNB switches a part of bearers of theUE from a pico base station 1 to a pico base station 2 and otherscenarios.

In step 601, a source eNB sends a second cell (Scell) setup requestmessage to a pico to request the pico to allocate resources for a partof ERABs of a UE. The message contains identifiers of the ERABs, aparameter of Quality of Service (QoS) of the ERABs and an uplink GTPTEID. The pico cell assigns a downlink TEID and a transport layeraddress for the requesting ERABs.

In step 602, the pico base station sends a Scell setup response messageto the eNB. The message contains a list of accepted ERABs. The list ofaccepted ERABs contains an identifier of an ERAB and a downlink TEID anda transport layer address assigned to the ERAB by the pico base station.The pico base station notifies the eNB of an unaccepted ERAB in eitherof the following two manners. Manner I, an implicit notification manner:an ERAB contained in the Scell setup request message but not containedin the list of accepted ERABs of the Scell setup response message is anunaccepted ERAB. Manner II: including in the Scell setup responsemessage a list of unaccepted ERABs, the list of unaccepted ERABscontaining an identifier of an unaccepted ERAB and/or a reason why theERAB is not accepted.

In step 603, the eNB reconfigures the UE. The eNB sends an RRCreconfiguration request message to the UE and the UE sends an RRCreconfiguration response message to the eNB.

In step 604, the eNB sends a path switching request message to the MME.The eNB notifies the MME of information on an ERAB not switched orreleased. The method in which the eNB notifies the MME of information onan ERAB not switched or released is the same as that in step 301 andthus will not be repeated herein. The eNB notifies the MME that a newMME UE S1AP ID does not need to be assigned and the MME UE S1AP ID priorto switch is to be reused. The manner in which the eNB notifies the MMEthat a new MME UE S1AP ID does not need to be assigned is the same asthat in step 401 and thus will not be repeated herein.

There are the following two security processing mechanisms for ascenario where a eNB remains unchanged and only a part of bearers isswitched to a pico or a eNB remains unchanged and bearers served by pico1 are switched to a pico 2.

Manner I: the security context of the UE is updated at the UE and at thenetwork side as it is in normal switch. In this manner, the manner inwhich the MME processes a security mechanism after receiving the pathswitching request message is the same as that in the prior art and thuswill not be repeated herein.

Manner II: the security context of the UE is not updated at the UE andat the network side and the security context of the UE prior to theswitch is reused. In this manner, the eNB notifies the MME that a newsecurity context is not needed and the security context of the UE priorto the switch is to be reused. The manner in which the eNB notifies theMME is the same as that in step 501 and thus will not be repeatedherein. The MME contains the security context prior to the switch in apath switching request conformation message in step 607.

In step 605, for those unchanged bearers in the path switching requestmessage in step 604, the MME reserves the bearer unchanged and does nottrigger a bearer deactivation process. The MME triggers a bearerdeactivation process for a bearer released in an access network.

The MME keeps the SGW serving the UE unchanged and does not select a newSGW if there is a bearer remaining unchanged.

The MME sends a modify bearer request message to the SGW. The method inwhich the MME notifies the SGW of a bearer to be switched and a bearerremaining unchanged is the same as that in step 302 and thus will not berepeated herein. For a bearer remaining unchanged, the SGW does notdiscard a downlink data packet when receiving it. The SGW sends adownlink data notification to the MME.

In step 606, the SGW sends a modify bearer response message to the MME.

In step 607, the MME sends a path switching request confirmation messageto the eNB. The message contains the MME UE S1AP ID that was used forthe UE prior to the switch.

Thus, the flow of the method of embodiment I end.

Embodiment II of supporting switch in accordance with the presentinvention is shown in FIG. 7. This embodiment can be used where the eNBserving a UE is changed and a pico base station remains unchanged. AeNB1 switches a control plane for the UE and a bearer of the eNB1 to aeNB2.

In step 701, the eNB1 sends a switch request message to the eNB2. Themessage contains context information of the UE at the pico, and thecontext information of the UE at the pico contains a base stationidentifier of the pico or a cell identifier of the UE at the pico. Thecontext information of the UE at the pico also contains an eNB UE S1APID assigned to the UE by the pico. The context information of the UE atthe pico contains a list of bearers' information remaining unchanged atthe pico. The bearers' information at the pico contains identifiers ofthe bearers remaining changed.

In step 702, the eNB2 sends a switch response message to the eNB1.

In step 703, the eNB1 reconfigure the UE. The eNB1 sends an RRCreconfiguration request message to the UE and the UE sends an RRCreconfiguration response message to the eNB2.

In step 704, the eNB2 sends a path switching request message to the MME.The eNB2 notifies the MME of information on an ERAB not switched orreleased (remaining unchanged). The method in which the eNB notifies theMME of information on an ERAB not switched or released is the same asthat in step 301 and thus will not be repeated herein.

In step 705, for those unchanged bearers in the path switching requestmessage in step 704, the MME reserves the bearer unchanged and does nottrigger a bearer deactivation process. The MME triggers a bearerdeactivation process for a bearer released in an access network.

The MME keeps the SGW serving the UE unchanged and does not select a newSGW if there is a bearer remaining unchanged.

The MME sends a modify bearer request message to the SGW. The method inwhich the MME notifies the SGW of a bearer to be switched and a bearerremaining unchanged is the same as that in step 302 and thus will not berepeated herein. For a bearer remaining unchanged, the SGW does notdiscard a downlink data packet but reserves the downlink data packetwhen receiving it. The SGW sends a downlink data notification to theMME.

In step 706, the SGW sends a modify bearer response message to the MME.

In step 707, the MME sends a path switching request confirmation messageto the eNB2.

Thus, the flow of the method of embodiment II ends.

As can be seen from the above detailed implementation of the presentinvention, in accordance with the present invention, in a case where aUE moves in a small cell scenario, a core network can be notified ofswitch of bearers correctly and an MME will be notified of bearersremaining unchanged and thereby the MME reserves these bearers. Thus, itis avoided that the MME deletes the bearers remaining unchanged, anddata loss is avoided. And, in a case where a part of bearers areswitched, the MME uses an MME UE S1AP ID assigned to the UE prior to theswitch and will not assign a new MME UE S1AP ID to the UE. Thereby, itis avoided that two logical connections of the UE appear in the sameinterface, and successful performing of the switch is ensured. Further,in a case where a part of bearers are switched, the MME may not assign anew security context and reuse a security context prior to the switch.Thereby, it will not result in that the NCCs at the UE and at thenetwork side do not match, and thus performing of the switchsuccessfully and a service continuity is ensured.

The foregoing is only preferred embodiments of the present invention andis not for use in limiting this invention. Any modification, equivalentreplacement or improvement made in accordance with the spirit andprinciples of the present invention is included in the protection scopeof the present invention.

1-11. (canceled)
 12. A method of a base station, the method comprising:transmitting, to a mobility management entity (MME), a request messagerequesting modification for one or more bearers; and receiving, from theMME, a confirmation message in response to the request message, whereinthe request message comprises first information on at least one bearerto be modified and second information on at least one bearer whichremains unmodified.
 13. The method of claim 12, wherein the firstinformation comprises at least one identifier of the at least one bearerto be modified.
 14. The method of claim 12, wherein the secondinformation comprises at least one identifier of the at least one bearerwhich remains unmodified.
 15. The method of claim 12, wherein theconfirmation message comprises a MME UE S1AP ID of a terminal.
 16. Themethod of claim 12, wherein the MME transmits, to a serving gateway, amodify bearer request message which comprises information on the atleast one bearer to be modified and information on the at least onebearer which remains unmodified based on the request message.
 17. Amethod of a mobility management entity (MME), the method comprising:receiving, from a base station, a request message requestingmodification for one or more bearers; and transmitting, to the basestation, a confirmation message in response to the request message,wherein the request message comprises first information on at least onebearer to be modified and second information on at least one bearerwhich remains unmodified.
 18. The method of claim 17, wherein the firstinformation comprises at least one identifier of the at least one bearerto be modified.
 19. The method of claim 17, wherein the secondinformation comprises at least one identifier of the at least one bearerwhich remains unmodified.
 20. The method of claim 17, wherein theconfirmation message comprises a MME UE S1AP ID of a terminal.
 21. Themethod of claim 17, further comprising: transmitting, to a servinggateway, a modify bearer request message which comprises information onthe at least one bearer to be modified and information on the at leastone bearer which remains unmodified based on the request message.
 22. Abase station of a wireless communication system, the base stationcomprising: a transceiver to transmit and receive to and from a mobilitymanagement entity (MME); and a controller configured to: control thetransceiver to transmit, to a mobility management entity (MME), arequest message requesting modification for one or more bearers, andreceive, from the MME, a confirmation message in response to the requestmessage, wherein the request message comprises first information on atleast one bearer to be modified and second information on at least onebearer which remains unmodified.
 23. The base station of claim 22,wherein the first information comprises at least one identifier of theat least one bearer to be modified.
 24. The base station of claim 22,wherein the second information comprises at least one identifier of theat least one bearer which remains unmodified.
 25. The base station ofclaim 22, wherein the confirmation message comprises a MME UE S1AP ID ofa terminal.
 26. The base station of claim 22, wherein the MME transmits,to a serving gateway, a modify bearer request message which comprisesinformation on the at least one bearer to be modified and information onthe at least one bearer which remains unmodified based on the requestmessage.
 27. A mobility management entity (MME) in a wirelesscommunication system, the MME comprising: a transceiver configured totransmit and receive to and from a base station and a serving gateway;and a controller configured to: control the transceiver to receive, froma base station, a request message requesting modification for one ormore bearers, and transmit, to the base station, a confirmation messagein response to the request message, wherein the request messagecomprises first information on at least one bearer to be modified andsecond information on at least one bearer which remains unmodified. 28.The MME of claim 27, wherein the first information comprises at leastone identifier of the at least one bearer to be modified.
 29. The MME ofclaim 27, wherein the second information comprises at least oneidentifier of the at least one bearer which remains unmodified.
 30. TheMME of claim 27, wherein the confirmation message comprises a MME UES1AP ID of a terminal.
 31. The MME of claim 27, wherein the controlleris further configured to control the transceiver to transmit, to aserving gateway, a modify bearer request message which comprisesinformation on the at least one bearer to be modified and information onthe at least one bearer which remains unmodified based on the requestmessage.